Precast　concrete　structure　has　many　advantages,　but　the　assembled　seam　will　affect　potentially　the　overall　seismic　performance　of　structure.　Based　on　the　sidewall　joint　located　in　the　bottom　of　assembled　monolithic　subway　station,　the　main　objectives　of　this　study　are,　on　one　hand　to　present　an　experimental　campaign　on　the　seismic　behavior　of　precast　sidewall　joint　(PWJ)　and　cast-in-place　sidewall　joint　(CWJ)　subjected　to　low-cycle　repeated　loading,　and　on　the　other　hand　to　explore　the　effect　of　shape　and　position　of　assembled　seam　on　load　carrying　capacity　and　crack　width　of　precast　sidewall　joint.　Two　full-scale　specimens　were　designed　and　tested.　The　important　index　of　failure　pattern,　loading　carrying　capacity,　deformation　performance　and　crack　width　were　evaluated　and　compared.　Based　on　the　test　results,　a　series　of　different　height　and　variably-shape　of　assembled　seam　of　precast　sidewall　joint　were　considered.　The　test　and　numerical　investigations　indicate　that,　(1)　the　carrying　capacity　and　deformation　capacity　of　precast　sidewall　and　cast-in-place　sidewall　were　very　similar,　but　the　crack　failure　pattern,　bending　deformation　and　shearing　deformation　in　the　plastic　hinge　zone　were　different　obviously;　(2)　the　influence　of　the　assembled　seam　should　be　considered　when　precast　underground　structures　located　in　the　aquifer　water-bearing　stratum;　(3)　the　optimal　assembled　seam　shape　and　position　can　be　suggested　for　the　design　of　precast　underground　concrete　structures　according　to　the　analysis　results.